1. Field of the Invention
The present invention relates to the field of interactive media systems, and more particularly, to a method and system for providing video cassette recorder (VCR) control of an interactive media system.
2. Background of the Invention
Interactive media system providers (referred to herein as service providers) have long been offering services that permit subscribers to purchase movies or special events for in-home viewing. These services enable a subscriber to browse a library of live and pre-recorded programs, to order a program, and to watch that program on the subscriber""s home viewing equipment. Typical variations of these services include pay-per-view, near video-on-demand (NVOD), and video-on-demand (VOD). Pay-per-view services usually offer live broadcast events that are shown only once, such as Wrestlemania(trademark) or boxing events. Near-video-on-demand services typically deploy continuous video streams at regular intervals, e.g., the same movie is shown for a whole day starting every fifteen minutes. Finally, video-on-demand services typically deliver individual media streams to subscribers immediately upon ordering. Overall, subscribers greatly value these services for their convenience in avoiding such difficulties as traveling to rent and return a video cassette or digital video disc (DVD) from a retail vendor.
Although some of these services deliver live event broadcasts or continuous media streams to multiple subscribers, the present invention is directed to the typical video-on-demand service, in which a pre-recorded program is delivered through an individual media stream to an individual subscriber. In such a case, the program is digitally encoded, stored on a server, and transmitted to a subscriber upon ordering.
To further attract subscribers to these interactive media services, service providers have added viewing functions that emulate the operation of a video cassette recorder (VCR). U.S. Pat. No. 5,357,276 to Banker, et al. discloses one such method of providing video-on-demand with VCR-like functions. Examples of these VCR functions include pause, rewind, and fast-forward. In this manner, subscribers can order a program and not be constrained by a continuous, unstoppable showing. Instead, the enhanced service gives the subscribers control over the delivery of the program and increased viewing flexibility. For example, with VCR-like functions, a subscriber can pause the viewing of an ordered program to accommodate such interruptions as telephone calls or trips to bathroom. In addition, using the rewinding function, a subscriber can return to and replay a favorite movie scene or perhaps return to a critical point in a program to ascertain missed information. Thus, subscribers have come to appreciate interactive media services with VCR-like control and will pay a premium to use them.
As used herein, xe2x80x9cVCR-like controlxe2x80x9d and xe2x80x9cVCR controlxe2x80x9d are synonymous terms describing the simulated video cassette recorder control that is applied to interactive media services. Likewise, xe2x80x9cVCR functionxe2x80x9d refers to a simulated video cassette recorder function, such as pause.
Although giving subscribers more viewing control increases subscribership and revenues, the added control presents a significant bandwidth problem for the service providers. Specifically, with unlimited VCR control, a subscriber can continuously use available bandwidth by, for example, watching a program or a portion of a program several times using the rewind function. Or, a subscriber might activate the pause feature for an extended amount of time and return to the program hours or days later. In effect, a subscriber with unlimited VCR control can consume the bandwidth allotted to his program for an indefinite amount of time. Further, for every subscriber tying up a portion of bandwidth, the capacity of the video server providing the service is reduced, resulting in, at some point, the service provider""s inability to sell another program to another subscriber.
To offset this bandwidth consumption, one method of limiting VCR control invokes a xe2x80x9ctime outxe2x80x9d function that terminates a subscriber""s ability to play the program. Typically, service providers have experimented with weekly or daily purchases, where a subscriber can view the program and use the VCR control without restriction during the allotted time period. However, service providers still find subscribers exploiting the service by watching a program repeatedly and consuming the allotted bandwidth for nearly the whole purchase period. Although the service providers can compensate for this repeated viewing by charging more for the service, subscribers tend to forego the service as cost increases.
To further limit the VCR control, service providers sometimes reduce purchase periods from weekly or daily durations to durations of a few hours. This time limit restricts the number of times a subscriber can rewind and replay a program, and simplifies the tasks of allocating bandwidth and opening capacity to other subscribers. However, timing out after just a few hours greatly reduces viewing flexibility and frustrates subscribers. As an example of this inflexible time out feature, a subscriber given five hours to watch a two hour movie might unexpectedly have to pause the program to take an important and lengthy telephone call. Even upon returning to the program within the five hours, the subscriber may not have enough time to watch the end of the movie because the remaining duration of the movie exceeds the time remaining before the time out. The result in these prior art time out systems is the termination of the movie, without warning and regardless of whether the subscriber reached the end of the movie. In addition, this time out method imposes a fixed viewing period that fails to factor in the length of a particular ordered program. Thus, a subscriber may think he has the same grace period for a longer program as for a shorter program, only to be cut off at the end of the viewing period.
Instead of timing out, some service providers base a completed program purchase on whether the subscriber views the end of the program. For example, the service provider can deactivate the VCR control once the subscriber reaches a certain point toward the end of the program, such as the rolling of credits. However, clever subscribers aware of the threshold point can still rewind, pause, and replay as often as they like and consume bandwidth to the detriment of the service provider. In addition, determining the point in a program at which to deactivate the VCR control is a tricky exercise, which can result in service behavior that annoys some subscribers but not others. For example, some subscribers may want the ability to rewind during the credits to catch an actor""s name while others simply turn off the program when credits begin.
Rather than limiting viewing time, some service providers restrict the total time that the VCR control can be applied. For example, a service provider may limit a subscriber to pressing the pause, rewind, or fast-forward functions for a total of 10 minutes. Pressing pause for 10 minutes is straightforward and is not problematic. However, in typical interactive media systems with VCR control, pressing rewind or fast-forward a certain amount of time shifts the viewing time a proportionally longer amount of time, e.g., in a system in which rewind and fast-forward speeds are 8 times faster than the viewing time speed, pushing the rewind or fast-forward button for 10 minutes backs up or advances the real time running of the program 80 minutes. Thus, following this example, for a movie or program shorter than 80 minutes, the subscriber could essentially rewind the whole program and watch it again, increasing the bandwidth consumption up to 80 minutes.
As another disadvantage, the interactive media systems that limit the duration of VCR control fail to credit a subscriber for pressing fast-forward and for actually reducing the bandwidth consumption. For instance, with VCR control limited to 10 minutes, if the subscriber pressed the fast-forward button for 10 minutes to check the name of an actor in the credits appearing 80 minutes later in the running time of the program, the subscriber would consume all 10 minutes of the VCR control. Further, because the interactive media systems that limit VCR control fail to recognize that pressing fast-forward reduces bandwidth and fail to credit the subscriber with the reduced bandwidth, the subscriber would have no more (credited) time for VCR control and would be unable to rewind to the original program location. (If the subscriber were to rewind to the original program location, the net change in bandwidth consumption would only be the sum of the 10 minutes it took to press fast-forward, the minute or so it took to read the credits, and the approximately 10 minutes it took to return to the original program location.)
Similarly, these interactive media systems fail to allow a subscriber to freely rewind and fast-forward to review prior segments and return to previous viewing locations. For instance, with VCR control limited to 10 minutes, if a subscriber backed up 80 minutes in a program to replay a favorite scene, the subscriber could not fast-forward to the previous viewing time to resume watching the rest of the program. Instead, after backing up 80 minutes and using 10 minutes of rewind/pause/fast-forward time, the subscriber would have to wait 80 minutes of real-time viewing to return to the location from which the subscriber began rewinding.
Alternatively, instead of limiting the amount of time a subscriber can rewind or fast-forward, a service provider can limit the amount of time traversed in the program""s running time. For instance, the service provider would limit the amount of time traversed in the program""s running time to 10 minutes, rather than limiting the pause/rewind/fast-forward time to 10 minutes. However, based on the 1:8 ratio, this limit would leave the subscriber with only 1.25 minutes of VCR control-hardly enough to satisfy subscribers and encourage interactive media purchases.
The present invention is a system and method for providing flexible subscriber control of an interactive media without unnecessarily consuming bandwidth capacity. Broadly stated, the present invention establishes a viewing time window in which a subscriber can watch an ordered program, enables the subscriber to freely pause, rewind, and fast-forward the program so long as the end of the program does not exceed the end of the window, automatically tracks the remaining program running time against the time remaining in the window, deactivates the pause and rewind features if the remaining program running time equals the time remaining in the window, and reactivates the pause and rewind features if the program is fast-forwarded such that the time remaining in the window exceeds the remaining program running time. The present invention provides subscribers with VCR control of interactive media programs, yet reasonably limits that control to conserve the bandwidth resources of service providers. Thus, subscribers receive a quality media delivery service that fulfills their requirement for VCR functionality, while the service providers conserve system resources, enlist more subscribers, and maximize profits.
The present invention can be implemented in any interactive media system that delivers video streams. Generally, the interactive media system will have a data storage device of finite capacity, e.g., a video server, that stores video data and delivers that video data in video streams. Preferably, the video streams are prerecorded programs. Also, preferably, the interactive media system is an interactive television system that supports services such as pay-per-view and video-on-demand. However, in another preferred embodiment of the present invention, the interactive media system is an internet-based interactive media system, in which video streams are downloaded through the internet and played at a subscriber""s personal computer or other viewing device.
The present invention establishes the length of the viewing time window based on a selected multiple of the program running time, preferably between roughly 1.5 and 2. For example, with a multiplier of 1.5, if a movie""s running time is 2 hours, the viewing time window is 1.5xc3x972 hours, or 3 hours. During these 3 hours, the subscriber may pause, rewind, or fast-forward, subject to the limitation that the movie must end within the 3 hour viewing time window. Using a multiplier carries the advantage of accounting for the length of the program instead of imposing inflexible cut-off times like those of the prior art. Thus, a subscriber has a proportionally equal grace period for both short and long programs and is not short-changed on VCR control when ordering long programs. In addition, different multipliers could be applied to programs of different lengths, e.g., a long 4 hour movie could have a multiplier of 2, while a short 1-xc2xd hour movie could have a multiplier of 1.5.
In the preferred embodiment of the present invention, the service provider determines the appropriate multiplier based on such factors as the capacity of the video server, the projected subscriber use of the service, the running times of available programs, and the minimum acceptable VCR control time, perhaps based on consumer satisfaction surveys. The appropriate multiplier varies among different service providers and different interactive media systems. However, this feature of the present invention is easily modified to accommodate the system requirements of each service provider and to accommodate the changing usage patterns of an individual system.
Once an appropriate multiplier is determined, the present invention continually tracks the remaining movie running time against the time remaining in the viewing time window, automatically prevents the subscriber from exceeding the end of the viewing time window, and reports the status of the running time and viewing window time to the subscriber. In a preferred embodiment of the present invention, during the showing of an ordered program, as a subscriber pauses, rewinds, and fast-forwards, the present invention calculates the time remaining in the viewing time window by subtracting the elapsed viewing time from the total viewing time window and calculates the remaining movie running time using either an end time method or a time stamp method.
The end time method instantaneously calculates the effects of the VCR control actions on the end time of the movie. For pausing, the present invention simply adds the duration that the pause is activated to the previous end time of the program. For rewinding, the present invention adds the amount of program time rewound plus the duration that the rewind function is activated to the previous program end time. For fast-forwarding, the present invention subtracts the amount of program time forwarded, minus the duration that the fast-forward function is activated, from the previous program end time. For interactive media systems that do not provide program time stamps, the end time method is the preferred method for calculating the remaining movie running time.
As an alternative to the end time method, the time stamp method calculates the remaining movie running time by subtracting the time stamp of the program video stream from the total program duration. For interactive media systems that do provide program time stamps, the time stamp method is the preferred method for calculating the remaining movie running time.
To prevent the program from ending beyond the viewing time window and the subscriber""s missing the program end, the present invention deactivates certain VCR functions. Thus, when the calculations described above show that the program end time equals the end of the viewing time window, the present invention deactivates the pause and rewind functions (because these functions extend the program end time). However, the present invention still provides the fast-forward function and, if activated, tracks its effects on the program end time. In this manner, the present invention recognizes that the subscriber has shortened the duration of the remaining program time (and reduced bandwidth consumption) such that the program end time is before the end of the viewing time window. As a result, the present invention reactivates the pause and rewind functions to give the subscriber the opportunity to again use the entire viewing time window.
In addition to pause, rewind, and fast-forward, the present invention also supports a stop function and a scene jump function. The stop function performs identically to the pause function, except that the screen is blanked instead of frozen. In conjunction with the stop function, the present invention could also allow a subscriber to start the movie over if enough time remained in the viewing time window (which would essentially be identical to the rewind function). The scene jump function would provide a menu of scenes from which to choose, similar to digital video disc formats. After a scene is chosen, the present invention would jump to that scene and play it. The scene jump function would operate similarly to the rewind and fast-forward functions, except that the amount of time the subscriber views the menu would be added to the program end time, as if the subscriber pressed pause while viewing the menu.
Thus, the interactive media VCR control of the present invention limits a subscriber""s ability to consume bandwidth capacity yet provides a satisfactory viewing experience. The method and system for providing this VCR control confines the bandwidth consumption to within a maximum value to enable a service provider to properly allocate video server resources. The VCR control supports the traditional VCR functions such as pause, rewind, and fast-forward, but limits their use to conserve bandwidth capacity, and monitors their use and advises the subscriber of any corresponding viewing limits. Finally, the system and method monitors a subscriber""s use of the VCR control and automatically deactivates or activates the control as necessary to complete the showing of a program within a purchase period.
Accordingly, it is an object of the present invention to provide a system and method for providing interactive media VCR control that limits a subscriber""s ability to consume bandwidth capacity yet provides a satisfactory viewing experience.
It is another object of the present invention to provide interactive media VCR control that confines bandwidth consumption to within a maximum value to enable a service provider to properly allocate video server resources.
It is another object of the present invention to limit a subscriber""s viewing control of a program, while still permitting enough flexibility to satisfy the subscriber""s preference for VCR control.
It is another object of the present invention to provide interactive media VCR control that supports traditional VCR functions such as pause, rewind, and fast-forward, but limits their use to conserve bandwidth capacity, and monitors their use and advises the subscriber of any corresponding viewing limits.
It is another object of the present invention to provide a system and method that monitors a subscriber""s use of VCR control and automatically deactivates or activates VCR functions as necessary to complete the showing of a program within a purchase period.